Distillation process for separating products of carbon tetrachloride fluorination



A. F. BENNING 7 2,450,415 DISTI'LLA'IION PROCESS FOR SEPARATING PRODUCTS OF CARBON TETRACHLORIDE FLUORINATION I5 Sheets-Sheet 1 Filed Nov. 19 1946 tub: kt mm N wt INVENTOR.

ANTHONY F. BENNING BY KMKW AITORNEY 5, 9 v A. F. BENNING 2,450,415

DISTILLATION PROCESS FOR SEPARATING PRODUCTS OF CARBON TETRACHLORIDE FLUORINATION 5 Sheets-Sheet 2 Filed NOV. 19, 1946' NGI INVENTOR.

ANTHONYF. BENN/NG ATTORNEY Oct. 5, 1948. C A. F. BENNING DISTILLA'I'ION PROCESS F OR SEPARATING PRODUCTS OF CARBON TETRACHLORIDE FLUORINATION 3 Sheets-Sheet 3- Filed NOV. 19, 1946 G W N a 1 m N N W E I3 4298 m B. n x F k :8 W208 Y KS3 N Lt T N A v. B.

3.33am on $38 m w I ATTORNEY Patented Oct. 5, 1948 UNITED DISTILLATION PROCESS FOR SEPARATING PRODUCTS OF CARBON TEIRACHLORIDE FLUORINATION Anthony F. Benning,woodstown, N. J., assignor to Kinetic Chemicals, Inc., Wilmington, Del., a

corporation of Delaware I November 19, 1946, Serial No. 710,890

Application 9 Claims. (Cl. 202-51) This invention relates to a process for separating valuable componentsfrom the reaction mixture obtained in the fluorination of' carbon tetrachloride.

In the fluorination of carbon tetrachloride in the presence of an antimony catalyst as it has been carried out heretofore, there is produced a reaction mixture comprising mainly H01, 00121: and CClaF with small proportions of HF and usually with small amounts of unreacted 0014. The separation of the valuable components of such mixture has been attended with considerable difiiculty. The usual procedure has been to wash the reaction mixture with water and sodium hydroxide solution to remove the acidic components, drying and condensing the washed products and then subjecting to fractional distillation to remove the dichlorodifluoromethane. During the reaction, only about 50% to 75%. of the 0014 is converted to CChFz so that the reaction mixture contains about 58 mole per cent of H01, about 21 mole per cent of CClzFz, about 16 mole per cent of CChF and smaller amounts of HF and 0014. This requires the use of large size equipment to wash, dry and condense the large amounts of CClaF and other organic products in the reaction mixture. Also, substantial amounts of valuable organic products are lost by solution in the wash water. This procedure further involves the loss of valuable H01 in the form of an aqueous solution contaminated with HF and organic products. Furthermore, when it was attempted to fractionally distill the reaction mixture, it was found that the distillation characteristics of the various components varied so much and were so inconsistent that, prior to my invention, it was not possible to carry out an efficient and economical separation.

It is an object of the present invention to provide a process for recovering the valuable components from a reaction mixture obtained by fluorinating carbon tetrachloride. Another object is to provide a process for separating diportion of dissolved CClzFz, which layers are separated. The separated CClzFz may then be passed to a scrubber where it is washed with water and with aqueous sodium hydroxide solution to remove HF. The und-istilled portion of the reaction mixture, comprising CClaF and unreaoted 0014, and the separated HF may then be recycled for further reaction.

Other objects of my invention may be accomplished by effecting the layer separation imme diately following the H01 distillation, that is, by

chlorodifluoromethane from the reaction mixture obtained by fluorinating 0014. A further object is to provide a process for recovering H01 in a usable form from the reaction mixture obtained by fiuorlnating 0014. Other objects are to advance the art. Still other objects will appear hereinafter.

some of the above and other objects of my invention may be accomplished by subjecting a reaction mixture, comprising mainly H01, CClzFz and CChF and small proportions of HF, to anhydrous fractional distillation under pressures of from about 40 to about 200 pounds per square inch gauge and at temperatures of from about -63 0. to about -20 C. adjusted to the pressures to distill off substantially pure anhydrous HCl while retaining the rest of the mixture in the still. The mixture remaining in the still may subjecting the still residue from the H01 dis-' tillation to a layer separation. I his may be coupled with operation of the reflux column above the reaction vessel so that no or not more than traces of CClaF and 0014 appear in the reaction mixture passing to the H01 distillation unit.

I have found that, by my process, I am able to effectively separate the reaction mixture into its valuable components in an easy and economical manner and to largely overcome the objections of the method previously employed. Only relatively small amounts of material are subjected to the washing, drying and condensing steps, whereby large economies are effected in the process and in the apparatus employed. Furthermore, the

H01 is recovered in a commercially valuable and usable form. There is also substantially complete recovery of organic reactants and products,

since none is lost by solution in the scrubbing'water. Furthermore, a large saving of HF is obtained by separation and recycling of the HF layer, the CClzFz dissolved therein being unobjectionable since it will .not be further fiuorinatedand will return in the reaction mixture. It will thus be apparent that, by my process, I am able to effectively recover the valuable components of the reaction mixture in a simple and easy manner and to effect large economies in the process and in the apparatus.

In order to more clearly illustrate my invention and the best anodes of carrying the same into effect, my invention will be described in moredetail with reference to the accompanying drawings which illustrate pref-erred forms of apparatus, shown somewhat diagrammatically, which may be employed for carrying out my invention.

The apparatus shown in a reaction vessel 10, a reflux column Fig. 1 of the drawings 3 l2, a dephlegmator ,a catch tank It. a reflux column 28 and a dephlegmatosr 22, all connected 4 plete separation of the CClzF'a and HF from the rest of the reaction mixture.

The mixture of CClaFi and HF from the dephlegmator 28 may be passed directly to a scrubstill pot I8 to the reflux column 28. The dephlegmotor 28 is connected to a condenser 29 and a se tling tank 80 through suitable conduits. The still pot 24 is provided with a conduit for withdrawing still residues therefrom and recycling them to the reaction vessel l0. The settling tank 80 is provided with a member 82 for indicating the level of the interface between the two layers. A conduit is provided for withdrawing the HF layer from the settling tank 80 and recycling it to the reaction vessel l0. Another conduit is provided for withdrawing the CClaFa layer from the tank 80 and conducting it to a. scrubber, not shown.

In operation, CC14 and HF are passed to the reaction vessel l0, containing a fluorination catalyst, wherein the C014 is fluorinated to produce L CClzFz and other products. A suitable catalyst may be prepared by placing about 400 parts of SbCls and about 40 parts of SbCls in the reaction vessel and then passing HF through the mixture until the fluorine content therein is about 1% to about 7%. The reaction mixture is passed from the reaction vessel through the reflux column l2 and dephlegmator ll, operated to retain C014 and CClsF for maximum conversion to CClzFa. The reaction products then pass to the catch tank [6 wherein they are freed from entrained catalyst, such as antimony salts, which is returned to reaction vessel in. The gaseous reaction mixture is compressed into the middle of the reflux column 20, employing a pump or compressor where necessary. The mixture entering the reflux column 20 is gaseous or'partially liquid and partially gaseous depending upon the temperature and pressure.

The reflux column 20 and the dephlegmator 22 are operated at temperatures, corresponding to the pressure employed, to distill ofi' substantially pure anhydrous HCl which is taken off at the top. With pressures of about 100 pounds per square inch gauge, the dephlegmator temperature will be from about 40 C. to about -50 C. I have found these last temperatures and pressures to be the most practical, but higher or lower pressures may be used with the temperatures adjusted accordingly. The still pot ill will be heated to give a pot temperature of about 25 C; to about C. but may be as high as 50 C. when large amounts of CClsF are present.

- The other components of the reaction mixture will pass to and be collected in the still pot l8. Theresidue in the still pot will be forced, by autogenous pressure, into the refiux column 26. There will be a slight pressure drop so that the reflux column 28 will normally operate at slightly lower pressures than the reflux column 20, e. g., at from about to about 70 pounds per square inch gauge. If desired, a compressor or other means can be included to increase the pressurein the reflux column 26, but this will generally be unnecessary. Preferably, the pressure in the reflux column 26 andthe dephlegmator 28 will be about pounds per square inch gauge. At the preferred pressure, the temperature in the dephlegmator will be from about 0 C. to about 5 C. By this means, there is obtained a substantially comber wherein the HF can be removed from the CCl2F2 by washing with water and sodium hydroxide solution. Preferably, however, the mixture of CCIaF: and HF will be condensed and passed to the settling tank 30. Upon settling. there is formed a layer of substantially anhydrous HF containing a minor proportion of dissolved CC12F2 and a layerof substantially pure CClzFa containing a small proportion of dissolved HF. The amount of dissolved CClzFz in the HF layer will vary with the temperature, belngabout 15% by weight'at 30 C. and about 25% by weight at +20 C. The amount of HF dissolved in the CClzFz layer will also be dependent upon the temperature, varying from about 0.4% by weight at 30 C. to about (1.9% at +20 C. Usually, the layer separation will be carried out at temperatures which will develop sufllcient pressure toforce the CC12F2 layer to the scrubbers by autogenous pressure. at. from about 0 to about 5 pound per square inch gauge, the temperature-of the layer separation will be from about -20 C. to about 0 C. Higher pressures in the scrubbers will require higher temperatures in the separator. If it is desired to carry out the layer separation at lower temperatures so as to reduce the amount of dissolved substances in the layers, pumps may be used to vforce the layers to those parts of the system operating at higher pressures.

The C C12F2 layer will be withdrawn from tank- 30 and passed to a scrubber to be washed free of HF by washing with water and aqueous sodium hydroxide solution. The HF layer is withdrawn and passed to the reaction vessel in or to storage.

The residue, in the still pot 24, comprises CCIaF and unreacted C014 which, preferably, will be returned to the reaction vessel ill for further fiuorinatlon.

The residues in the still pots l8 and 24 will preferably be allowed to build up until the pots are about half full and the residues will be drawn on" therefrom as necessary to maintain the pots about half full. If all of the still residue were removed from each pot, the stills would tend to operate erratically. By maintaining each still pot about half full of residue,

The HF layer will contain a minor proportion ofdissolved organic products, mainly CClzFa and CClaF, the amounts depending on the temperature. The CClzFz is soluble'in HF in the proportion of about 15% by weight at 30- C. and about 25% by weight at +20 C. The CClsF is soluble in HF in the proportion of about 6% by weight at -30 C. and about 9% by weight at +20 C. The total amount of organic products dissolved in theHF layer will be between about:

6% by weight at -30 C. and about 25% by weight at +20 C., depending on the relative proportions of CClsF to CClsFz. The organic layer will also contain a small proportion of dissolved With the scrubbers operating smoother and better I HF, the amount of which will vary with temperature and the ratio of COMP to CClzFa in the layer. HF is soluble in CChF: in an amount of about 0.4% by weight at -30 C. and about 0.9% by weight at C. HF is soluble in CClaF to the extent of about 0.2% by weight at C. and about 0.3% by weight at +20 C. The amount of HF, dissolved in the organic layer, will vary from about 0.2% to about 0.9% by weight at temperatures from -30 C. to +20 C. I

As in the case of the modification of Fig. l, the temperature of the layer separation in Figr 2 will usually be. such as to develop sufficient pressure to force the organic layer to the next stage of the system, that is to column 26. When column 26 is operated at 0 pounds per square inch gauge, the temperature of the layer separation will be from about 20 C. to about 0 C. When column 26 is operated at 100 pounds per square inch gauge, the temperature in the separator will be from about +25 C. to about C. If it is desired to carry out the layer separation at lower temperatures, then the layers to the desired parts of the system operating at higher pressures.

After the layer separation, the HF layer will be recycled to the reaction vessel ill or passed to storage and the organic layer will be passed to reflux column 26. The column 26 is provided for the fractional distillation of CChFa and HF from the rest of the organic products. Column 26 and dephlegmator 28 will be operated as in Fig. 1, that is at pressures of from about 0 to about 100 pounds per square inch gauge and temperatures of from about -36 C. to about +32 C. and preferably at about 40 pounds per square inch gauge and from about 0 C. to about 5 C. The mixture of CClzFz and HF from the dephlegmator 26 will be passed to scrubbers for washing with water and aqueous sodium hydroxide solution to remove the HF therefrom. The organic products from still pot 28 will be recycled to the reaction vessel ID for further fluorination.

By improving the efficiency of reflux column l2 as by converting it to an effective fractionating column, it is possible to eliminate substantially all of the CClaF and C014 sothat the reaction mixture leaving the dephlegmator ll comprises about 64 mole per cent HCl, about 32 mole per cent CClzFz, about 4 mole per cent HF and conpumps will be used to force tains no more than traces of under fluorinated compounds. This modification is also shown in Fig. 2, the parentheses about the CC13F and CCl4 indicating the substantial absence of such compounds from the reaction mixture. Under such circumstances, the catch tank l6 becomes unnecessary as all catalyst is also removed from the effluent gases, in the column l2. Also, under such conditions, the organic layer in the separator 30 will consist essentially of CClzF: containing dissolved HF which will be passed directly to the scrubbers as by by-pass line 23 of Fig. 2 thereby eliminating pct 24, column '26 and dephlegmator 28. In this modification, the separator 30 will be operated under the conditions set forth for that in Fig. 1.

Still further and preferred modifications are shown in Fig. 3 of the drawings wherein the residue from the still pct 16 is layer separation. The condenser is provided with a vent 44 for venting of! air or other gaseous inert material which may be accidentally introduced into the system. The liquid products drain into the settling tank 30 from the condenser 34. The

passed to a condenser 36 for cooling to the temperature desired for the to the scrubbers, as

HF layer containing dissolved organic products is drawn from the settling tank and recycled to the reactor M or passed to storage. The organic layer containing dissolved HF passes from the settling tank 60 into the reflux column 26. The column 26 is operated at temperatures and pressures corresponding to those in Figs. 1 and 2 to distill oil a mixture Of CC12F2 and HF which passes to condenser 24 where it is condensed and then passes to settling tank 60. The undistilled portion of the organic products in column 26 passes to the still pot 24 from which it is passed to reflux column 36 or to the scrubbers, depending upon the amount of CClaF in the reaction mixture. Where the reaction mixture, entering column 20,'contains substantial amounts of CClaF, with or without CCli, the column 38 is used to distill off. CClaF'z through dephlegmator 46- and then to the scrubbers, the CClsF and any CCl4 passing to still pot 36 and thento reactor Hi. When column I2 is so operated that the mixture entering column 20 contains substantially no CClaF or C014, the residue in still pot 26 is substantially pure CClaF: which is passed directly through by-pass line 42. eliminating column 68, pct 36.

Preferably, the layer separation in tank 30 will be operated at the equilibrium temperatures so that the organic layer will drain into column 26 by gravity. With column 26 operating at 40 to.

pounds per square inch gauge, the equilibrium temperature in tank 30 will be from 0 C. to 30 C.

The preferred pressures and temperatures will be about '70 pounds per square inch gauge in column 26 and about 15 C. to about 21 C. in tank 30.

The process of Fig. 3 has the advantage that the court, going to the scrubbers, is substantially free of HF so that essentially no HF is lost in the scrubbing liquor but practically all of the HF accumulates in the HF layer withdrawn from tank 30. I have found that HF and CClzFz form a pseudo azeotrope in which the ratio of HF to CClilFil is materially greater than the solubility of HP in the organic layer and which azeotrope boils about 6 C. below the boiling point of pure CClsFa. At 20 0., the equilibrium composition of such pseudo azeotrope vapor is about 8% by weight of HFand about 92% by weight of CC12F2.

This compares with the solubility of RF in CClzFz V of about 0.9% by weight at 20 C. Therefore. by adjusting the temperature in column 26 to a temperature at or above the, boiling point of the pseudo azeotrope but below the boiling point of pure CClzFz or of the mixture of CClzFz and CClsF, the vapors, passing from column 26 to condenser 34, will contain a materially higher ratio of HF to organic products than that in the organic layer passing to column 26 from tank 30. Thus, the HF is continuously stripped from the organic products in column 26 and the organic products in still not 24 will contain not more than traces of HF.

Commercial HF frequently contains small amounts of S02 (average is about 0.6% by weight) and moisture. The moisture is converted into COCh by reaction with 0014 in reaction vessel ID. The S0: and COClz appear in the gaseous reaction mixture passing to reflux column 20. In the.

systems of Figs. 1 and 2, the S02 and COClz do not present a serious problem since they pass out of the system with the CC12F2 and are removed therefrom by the scrubbing liquors.

In the system of Fig. 3, there IS a tendency for T the COClz to build up to a limited extent in the dephlegmator 40 and still The building up of the COClz in the system can be materially reduced by removing the 'COCl; from the HF layer by any suitable means before returning such layer to reaction vessel l0. This may be done conveniently by fractional distillation', the COCls forming a constant boiling mixture with HF which, at 25 pounds per square inch gauge, contains about 77% by weight of CD01:

' and 23% by weight oil-IF and boils at about The presence of SO: in the reactionmixture, presents a more serious problem inthe system of Fig. '3. It forms a ternary mixture of. the approximate composition; 84% by'weight of S02 and 3.5% by weight of HF. This mixture balls at +4 C. under a pressure of 44 pounds per'square inch gauge and at 36' C. at 1 atmosphere; Accordingly, from the orgar'iic products in column 26 and tends to accumulate in the reflux circuit comprising column 26, condenser 34 and tank 30. The S02 passes out of tank 30 with the HF layer faster than it is introduced into the system with fresh commercial HF. However, ii the HF layer is recyledto reaction vessel I without purification, the S02 therein is retained in the system, passing through the reaction vessel l0 and reappearing in the reaction mixture. The building up of SO: in the system to an objectionable extent can be prevented by removing the S02 from the separated HF layer by any suitable means before introducing such HF layer into reaction vessel H). A convenient method is to subject the separated HF layer to fractional distillation, either continuously or periodically, to distill oil the ternary mixture. I have used, for this purpose, a reflux column, dephlegmator and still pot such as 26, 28 and 24, respectively, as'in Figs. 1 and 2, with pressures of from about 30 to about 90 pounds per square inch gauge in the reflux column and temperatures of from about C. to about C. in the dephlegmator. Freferred conditions are about 70 pounds per square inch gauge and +15 C., the temperatures in the still pot being about 75 C. to about 85 C.

The apparatus and the operation thereof, as above described, illustrates one type of apparatus for a continuous process. ratus may be substituted therefor. Also, the process may be operated batchwise in suitable apparatus therefor. Furthermore, pressures, higher and lower than those disclosed, may be employed with suitable adjustment of the temperatures in accordance with the principles of my invention. Therefore, my invention is not to be limited to the speciflc'embodiments disclosed, but I intend to cover my invention broadly as in the appended claims.

This is a co'ntinuation-in-part of my copending application Serial No. 577,868, filed February 14, 1946, now' abandoned.

I claim:

1. The process of separating valuable components from a reaction mixture comprising HCl, HF, CChFz and CClsF, of the character of that obtained by the reaction of HF on'CCl4, which comprises the steps of subjecting the reaction mixture to anhydrous fractional distillation under pressures of from about 40 to about 200 pounds by weight of CClzFa, 12%

Other types of aPpa-' nents from a reaction sures to distill oil a mixture comprisingsubstantially the dichlorodifluoromethane and the hydrogen fluoride, condensing the distilled mixture, settling the condensed containing a minor proportion of dissolved dichlorodifluoromethane and a layer of dichlorodifluoromethane containing a small proportion of dissolved HF, and then separating the layers.

2. The process of separating valuable compomixture comprising HCl,

HF, CClzFz and CClaF, of the character of that obtained by the reaction of HF on CCl4, which the S02 is stripped comprises the steps of subjecting the reaction mixture to anhydrous fractional distillation under I pressures of about 100 pounds per square inch gauge and at about C. to about 40 C. to

' distill off the HCl as substantially pure anhydrous hydrogen chloride, then subjecting the remaining mixture to a further anhydrous fractional distillation under pressures of about 40 pounds per square inch gauge and at from about 0 C. to about 5 C. to distill off a mixture comprising substantially the dichlorodifluoromethane and the hydrogen fluoride, condensing the distilled mixture, settling the condensed mixture until it forms a layer of substantially anhydrous hydrogen fluoride dissolved dicontaining a minor proportion of chlorodifluoromethane and a layer of dichlorodifluoromethane containing a small proportion of dissolved HF, and then separating the layers.

3. The process of separating valuable components from a reaction mixture comprising HCl,

1 HF, CClzFz, C013! and C014, of the character of that obtained by the reaction of HF on C014, which comprises the steps of subjecting the reactionmixture to anhydrous fractional distillation under pressures of from about 40 to about 200 pounds per square inch gauge and at temperatures of from about 63' C. to about 20 0., adjusted to the pressures to distill off the HCl as substantially pure anhydrous hydrogen chloride, then subjecting the remaining mixture to a further anhydrous'fractional distillation under pressures of from about 0 to about 100 pounds per square inch gauge and at temperatures of from about 36 C. to about +32 C., adjusted to the pressures to distill off a mixture comprising substantially the dichlorodifluoromethane and the hydrogen fluoride, condensing the distilled mixture, settling the condensed mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dissolved dichlorodifluoromethane and a layer of dichlorodifluoro methane containing a small proportion of dissolved HF, separating the layers, and washing the separated dichlorodifluoromethane layer to remove the HF therefrom.

4. Theprocess of separating valuable components from a. reaction mixture comprising HCl, HF, CClzFz, CClaF and CCh, of the character of that obtained by the reaction of HF on C014, which comprises the-steps of subjecting the reaction mixture to anhydrous fractional distillation under pressures of about pounds per square inch gauge and at about 50? C; to about mixture until it forms a layer of substantially anhydrous hydrogen fluoride -40 CL to distill off the HCl as substantially pure anhydrous hydrogen chloride, then subjecting the remaining mixture to a further anhydrous fractional distillation under pressures of about 40 pounds per square inch gauge and at from about C. to about C. to distill off a mixture comprising substantially the dichlorodifluoromethane and the hydrogen fluoride, condensing the distilled mixture, settling the con densed mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dissolved dichlorodifluoromethane and a layer of dichlorodifluoromethane containing a solved HF, separating the layers, and washing the separated dichlorodifiuoromethane layer to remove the HF therefrom.

5. The process of separating valuable components from a reaction mixture comprising HCl, HF, CClzFa and CClsF, of the character of that obtained by the reaction comprises the steps or subjecting the reaction mixture to anhydrous fractional distillation under pressures of from about 40 to about 200 pounds per square inch gauge and at temperatures of from about -63 C. to about -20 C., adjusted to the pressures to distill off the HCl as substantially pure anhydrous hydrogen chloride, then settling the remaining mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dissolved organic products and a layer of organic products containing a small proportion of dissolved HF, separating the layers, and then subjecting the organic layer to an anhydrous fractional distillation under pressures of from about 0 to about 100 pounds per square inch gauge and at temperatures of from about -36 C. to about +32 0., adjusted to the pressures to distill off the CClaFn and dissolved HF.

6. The process of separating valuable components from a reaction mixture comprising HCl, HF, CClaFa and (301315, of the character of that obtained by the reaction of HF on CCl4, which comprises the steps of subjecting the reaction mixture to anhydrous fractional distillation under pressures of about 100 pounds per square inch gauge and at temperatures of from about -50 C. to about -40 C., to distill oil the HCl as substantially pure anhydrous hydrogen chloride, then settling the remaining mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion' of dissolved organic products and a layer of organic products containing a small proportion of dissolved HF, separating the layers, and then subjecting the organic layer to an anhydrous fractional distillation under pressures of about 40 pounds per square inch gauge and st temperatures of from about 0 C. to about 5 C. to distill off the CClzFa and dissolved HF.

I. The process of separating valuable components from a reaction mixture comprising l-ICl, HF, CClaFa and CClrF, of the character of that obtained by the reaction of HF on 0014, which comprises the steps of subjecting the reaction mixture to anhydrous fractional distillation under pressures of from about-40 to about 200 pounds per square inch gauge and at temperatures of from about -63 C. to about 2 0" 0., adjusted to the pressures to distill of! the H01 as substantially pure anhydrous hydrogen chsmall proportion of dis'-' of HF on C014, which 3 of dissolved organic products and a layer of organic products containing a small proportion of dissolved HF, separating the layers, then subjecting the organic layer to an anhydrous fractional distillation under pressures of from about 0 to about 100 pounds per square inch gauge and at temperatures of from about -36 C. to about +32 C., adjusted to the pressures to distill off CClzFz and the dissolved HF as a pseudo azeotrope containing HF in a higher concentration than will dissolve in CClzFa, condensing the pseudo azeotrope and settling it until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dissolved CClzFa and a layer of 'CClzF: containing a small proportion of dissolved HF, separating the last mentioned layers, returning the CClzFa layer to the last mentioned fractional distillation, and withdrawing from the last mentioned fractional distillation organic products substantially free of HF.

8. The process of separating valuable components from a reaction mixture comprising HCl,

HF and CClizFa of the character of that obtained ride, then settling the remaining mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion by the reaction of HF on CCl4, which comprises the steps of subjecting the reaction mixture to anhydrous fractional distillation under pressures of from about 40 to about 200 pounds per square inch gauge and at temperatures of from about 63 C. to about 20 C., adjusted to the pressures to distill off the HCl as substantially pure anhydrous hydrogen chloride, then settling the remaining mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dissolved CClzFa and a layer of. CClaFz containing a small proportion of dissolved HF, separating-the layers, and then removing the dissolved HF from the CClzFz layer.

9. The process of separating valuable components from a reaction mixture comprising HCl, HF and CClaFa of the character or that obtained by the reaction of HF on CCI4, which comprises the steps of subjecting the reaction mixture to anhydrous fractional distillation under pressures of from about 40 to about 200 pounds per square inch gauge and at temperatures of from about -63 C. to about -20 C., adjusted to the pressures to distill off the HCl at substantially pure anhydrous hydrogen chloride, then settling the remaining mixture until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dissolved CClsFa and a layer of CClaFz containing a small proportion of dissolved HF, separating the layers, then subjecting the CClzF'z layer to an anhydrous fractional distillation under pressures of from about 0 to about pounds per square inch gauge and at temperatures of from about -36 C. to about +32 C., adjusted to the pressures to distill off CClsFn and the dissolved HF as a pseudo azeotrope containing HF in higher concentration than will dissolve in CClaFe, condensing the pseudo azeotrope-and settling it until it forms a layer of substantially anhydrous hydrogen fluoride containing a minor proportion of dis-' solved CClaFa and a layer of CClaFr containing a small proportion of dissolved HF, separating Y the last mentioned layers, returning the CClsFz layer to the last mentioned fractional distillation, and withdrawing from the last mentioned fractional distillation CClaFa substantially free of HF.

' ANTHONY F. BENNING.

No references cited. 

